Stroller

ABSTRACT

There is provided a stroller allowing an operation for switching the conditions of the wheels in accordance with a position of the handle to be performed in a more stable and reliable manner. A stroller  10  includes: a frame part  20;  a handle  50  connected to the frame part so as to be swingable; caster mechanisms  60  and  80  configured to turnably hold wheels; and switch mechanisms  100   a  and  100   b  respectively including lock switching members capable of being pushed so as to be moved by the handle that is swung. The caster mechanisms are respectively provided with locking means capable of restricting a turning of the wheel. There are disposed transmission means  120  and  130  configured to operate the locking means in accordance with movements of the lock switching members.

FIELD OF THE INVENTION

The present invention relates to a stroller including a handle that is swingable between a forward inclined position and a rearward inclined position. In particular, the present invention pertains to a stroller in which wheels disposed on front legs or rear legs can be automatically switched, in accordance with a position of the handle, into a turnable condition or an unturnable condition relative to the back and forth direction of the stroller.

BACKGROUND ART

There have been conventionally known strollers for carrying a baby facing forward in the traveling direction. In addition, widely used in recent years are strollers including a handle that is swingable between a first position (front pushing position) at which the handle is inclined forward of a vertical axis when viewed from the lateral side, and a second position (back pushing position) at which the handle is inclined rearward of the vertical axis. In such a stroller, when the handle is arranged on the second position, an operator (parent) can push forward the stroller with the baby facing forward in the traveling direction, grasping the handle from a back side of the baby. On the other hand, when the handle is arranged on the first position, the operator can push forward the stroller with the rear legs facing forward in the traveling direction, grasping the handle from a side of the front legs on which the operator faces the baby.

In consideration of manipulability of the stroller, it is preferable that wheels disposed on the legs facing forward in the traveling direction are turnable relative to the back and forth direction, while wheels on the legs facing rearward in the traveling direction are unturnable relative to the back and forth direction. JP2002-284015A discloses a stroller in which the wheels disposed on the front legs and the rear legs can be automatically switched, in accordance with a position of the handle, into the turnable condition or the unturnable condition relative to the back and forth direction.

In the stroller disclosed in JP2002-284015A, sliding members (lock switching members) are slidably provided on the front legs. The sliding members are pushed to be slid by the handle which is being swung toward the first position (front pushing position), whereby the wheels can be switched to the turnable condition or the unturnable condition.

However, inclined angles of the front legs and a swinging range of the handle are set in relation to other structures of the stroller, in terms of comfortableness and manipulability. Thus, it is impossible in all the strollers to align a direction in which the handle pushes the lock switching member with a direction in which the lock switching member is slidable, i.e., a direction in which the front leg is extended. In this case, there is a possibility that the lock switching members cannot be smoothly slid by the swinging of the handle. In other words, an operation of the lock switching mechanism by the handle cannot be always performed in a stable and reliable manner. In the first place, depending on the overall structure of the stroller, it may be inappropriate to swing the handle up to a position on which the handle is located on the lateral sides of the front legs, with a view to facilitating grasping and operating of the handle. In this case, it becomes impossible to push the lock switching member by swinging the handle.

In the stroller of JP2002-284015A, the conditions of both the front wheels and the rear wheels are switched by the single lock switching member disposed on each of the front leg. This structure is advantageous in that the number of parts can be decreased. Meanwhile, there is a possibility that a switching operation cannot be performed in a stable and reliable manner.

DISCLOSURE OF THE INVENTION

The present invention has been made in view of this respect. The object of the present invention is to provide a stroller allowing an operation for switching the conditions of the wheels in accordance with a position of the handle to be performed in a more stable and reliable manner.

The stroller of the present invention is a stroller comprising: a frame part including an armrest, a front leg, and a rear leg, the front leg and the rear leg being connected to the armrest; a handle connected to the frame part so as to be swingable between a first position and a second position; a caster mechanism disposed at least on one of the front leg and the rear leg, the caster mechanism including a wheel, a wheel holder configured to rotatably and turnably hold the wheel, and a locking means capable of moving between a locking position for restricting a turning of the wheel and an unlocking position for enabling the turning of the wheel; a switch mechanism supported on the armrest of the frame part and, the switch mechanism including a lock switching member capable of being pushed so as to be moved by the handle that is swung toward the first position or the second position; and a transmission means disposed between the switch mechanism and the caster mechanism and configured to transmit a moving action of the lock switching member to the locking means so as to move the locking means from the unlocking position to the locking position or from the locking position to the unlocking position.

In the stroller of the present invention, it is preferable that a movable direction of the lock switching member is substantially parallel to a moving trajectory of a portion of the handle to be contact with the lock switching member when the handle is brought into contact with the lock switching member.

In addition, in the stroller of the present invention, the caster mechanism may include a caster mechanism for front leg disposed on a lower end of the front leg, and a caster mechanism for rear leg disposed on a lower end of the rear leg; the switch mechanism may include a first switch mechanism to be engaged with the handle resting on the first position and a second switch mechanism to be engaged with the handle resting on the second position, the first switch mechanism and the second switch mechanism being supported on the armrest; and the transmission means may include a first transmission means disposed between the first switch mechanism and one of the caster mechanism for front leg and the caster mechanism for rear leg, and a second transmission means disposed between the second switch mechanism and the other of the caster mechanism for front leg and the caster mechanism for rear leg. In such a stroller, it is preferable that when the handle rests on the second position, the turning of the wheel of the caster mechanism for rear leg is restricted, and that when the handle rests on the first position, the turning of the wheel of the caster mechanism for front leg is restricted. In such a stroller, the handle may be configured to be inclined forward on the first position and inclined rearward on the second position.

In addition, in the stroller of the present invention, an engagement member may be disposed on the armrest, the engagement member capable of being engaged with the handle so as to lock the handle on the first position, and the lock switching member of the first switch mechanism may be positioned near the engagement member.

Further, in the stroller of the present invention, an engagement member may be disposed on the armrest, the engagement member capable of being engaged with the handle so as to lock the handle on the second position, and the lock switching member of the second switch mechanism may be positioned near the engagement member.

Furthermore, in the stroller of the present invention, the transmission means may include a wire whose opposed ends are respectively fixed to the lock switching member of the switch mechanism and the locking means of the caster mechanism, and a tubular member held by the frame part; and the wire may pass through the tubular member so as to be slidable with respect to the tubular member.

In such a stroller, the tubular member may be extended in the front leg or the rear leg of the frame part. Alternatively, in such a stroller, the tubular member may be held on an outer surface of the front leg or an outer surface of the rear leg of the frame part.

According to the stroller of the preset invention, it is possible to perform an operation for switching the conditions of the wheels in accordance with a position of the handle in a more stable and reliable manner.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view for explaining an overall structure of a stroller in one embodiment of the present invention;

FIG. 2 is a side view of the stroller, with a handle thereof being arranged on a second position (backside pushing position);

FIG. 3 is a side view of the stroller, with the handle being arranged on a first position (face-to-face pushing position);

FIG. 4 is a side view showing a caster mechanism for front leg;

FIG. 5 is a longitudinal sectional view of the caster mechanism for front leg shown in FIG. 4, with a locking means being arranged on an unlocking position;

FIG. 6 is a longitudinal sectional view corresponding to FIG. 5, with the locking means being arranged on a locking position;

FIG. 7 is a sectional view taken along the line VII-VII in FIG. 6;

FIG. 8 is a side view of a caster mechanism for rear leg;

FIG. 9 is a longitudinal sectional view of the caster mechanism for rear leg shown in FIG. 8, with a locking means being arranged on a locking position; and

FIG. 10 is a partial side view of the stroller for explaining a switch mechanism.

MODE FOR CARRYING OUT THE INVENTION

One embodiment of the present invention will be described below with reference to the drawing.

FIGS. 1 to 10 are views for explaining a stroller in one embodiment of the present invention. FIGS. 1 to 3 show an overall structure of the stroller. As show in FIGS. 1 to 3, the stroller 10 includes a frame part 20 having front legs 22 and rear legs 24, and a handle 50 swingably connected to the frame part 20. Disposed on a lower end of the front leg 22 of the frame part 20 is a caster mechanism for front leg 60 having a front wheel 61. Disposed on a lower end of the rear leg 24 of the frame part 20 is a caster mechanism for rear leg 80 having a rear wheel 81.

In this embodiment, similarly to prevalent strollers (see, JP2006-117012A, for example), the stroller 10 is configured to be foldable. In the stroller 10 in this embodiment, it is both possible, by swinging the handle 50 with respect to the frame part 20, to steer the stroller 10 with the baby facing forward in the traveling direction, while an operator (parent) grasps the handle 50 from a back side of the baby, and to steer the stroller 10 with the rear leg of the stroller 10 facing forward in the traveling direction, while the operator grasps the handle from a side of the front leg on which the operator faces the baby.

In this specification, the terms “front”, “rear”, “up”, “down”, “back and forth direction”, and “up and down direction” with respect to the stroller mean, unless otherwise specified, “front”, “rear”, “up”, “down”, “back and forth direction”, and “up and down direction”, with respect to a baby in the unfolded stroller 10. More specifically, the “back and forth direction” of the stroller 10 corresponds to a direction connecting a lower left part and an upper right part in a plane of FIG. 1, and a right and left direction in a plane of each of FIGS. 2 and 3. Unless otherwise specified, the “front” is a side to which the baby in the stroller faces. The lower left side in the plane of FIG. 1 and the left side of the plane of each of FIGS. 2 an 3 correspond to the front side of the stroller 10. The “up and down direction” of the stroller 10 is a direction perpendicular to the back and forth direction, and is a direction perpendicular to the ground on which the stroller 10 rests. Thus, when the ground surface is a horizontal surface, the “up and down direction” represents a vertical direction. The “lateral direction” is a width direction, and is a direction perpendicular both to the “back and forth direction” and the “up and down direction”.

At first, as an overall structure of the stroller, the frame part 20 and the handle 50 are described. As shown in FIG. 1, the stroller 10 in this embodiment has substantially a symmetrical structure as a whole, with respect to a lateral center plane containing the back and forth direction. As shown in FIGS. 1 to 3, the frame part 20 in this embodiment includes a pair of legs 22 respectively disposed on the right side and the left side, a pair of rear legs 24 respectively disposed on the right side and the left side, a pair of armrests 28 respectively disposed on the right side and the left side, and a pair of connecting rods 26 respectively disposed on the right side and the left side.

The front legs 22, the rear legs 24, and the connecting rods 26 may be formed of tubular members, for example, pipes made of an aluminum alloy. Meanwhile, the armrests 28 may be formed of a resin, for example. An upper end of each of the front legs 22 is rotatably (swingably) connected to a front section of the corresponding (right or left) armrest 28. Similarly, an upper end of each of the rear legs 24 is rotatably (swingably) connected to the front section of the corresponding (right or left) armrest 28. An upper portion of each of the connecting rods 26 is rotatably (swingably) connected to a rear section of the corresponding (right or left) armrest 28.

The frame part 20 further includes a left lateral side connecting member 32 that connects the left front leg 22 and the left connecting rod 26, and a right lateral side connecting member 32 that connects the right front leg 22 and the right connecting rod 26. A front portion of each of the lateral side connecting members 32 is rotatably connected to an intermediate section of the front leg 22. A rear portion of each of the lateral side connecting members 32 is rotatably connected to a lower section of the connecting rod 26. The lateral side connecting member 32 may be formed of a plate member made of an aluminum alloy, for example. The frame part 20 further includes a left bracket 34 that connects the left rear leg 24 and the left connecting rod 26, and a right bracket 26 that connects the right rear leg 24 and the right connecting rod 26. Each of the brackets 34 is rotatably (swingably) connected, at one portion thereof, to an intermediate section of the rear leg 24, and is rotatably connected, at the other portion thereof, to a lower section of the connecting rod 26.

As laterally extending constituent elements, the stroller 10 in this embodiment includes a pair of front upper connecting stay 36 and a footrest 28 that connect the pair of front legs 22, and a rear upper connecting stay 40 that connects the pair of rear legs 24. A bendable guard member 42 connecting the pair of armrests 28 is detachably mounted on the respective armrests 28.

The handle 50 is swingably connected to the frame part 20 as structured above. As shown in FIG. 1, in this embodiment, the handle 50 includes a pair of linear portions 51 a extending substantially linearly in parallel with each other, and an intermediate portion 51 b that connects the pair of linear portions 51 a. The handle 50 generally has a substantially U-shape. Opposed ends of the U-shaped handle 50 are rotatably (swingably) connected to the corresponding brackets 34. A rotational axis line (swing center) of the handle 50 with respect to the brackets 34 corresponds to a rotational axis of the brackets 34 with respect to the connecting rods 26, and a rotational axis line of the connecting rods 26 with respect to the lateral side connecting members 32. Due to this structure, as shown in FIGS. 2 and 3, the handle 50 can be swung with respect to the frame part 20, and the linear portions 51 a of the handle 50 can be moved on the lateral sides of the armrests 28 along the armrests 28.

The handle 50 is provided, on the pair of linear portions 51 a capable of moving along the lateral sides of the armrests 28, with engagement members 55. Each of the engagement members 55 on the linear portions 51 a is configured to be slidable along the corresponding linear portion 51 a. In addition, the handle 50 is equipped, on the intermediate portion 51 b, with a remote operation device 53 for remotely operating sliding of the engagement members 55. On the other hand, as shown in FIGS. 2 and 3, each of the armrests 28 has a pair of engagement members 30 a and 30 b (engagement projections are omitted in FIG. 1) to be engaged with engagement members 55 for restricting rotation of the handle 50. By operating the remote operation device 53 so as to slide the engagement members 55 upward, the engagement members 55 and the engagement projections 30 a or 30 b can be disengaged from each other.

By engaging the front engagement projection 30 a and the engagement member 55 so as to be locked to each other, as shown in FIG. 3, the handle 50 is fixed on a first position (face-to-face pushing position) P1. When the handle 50 is fixed on the first position P1, the handle 50 adopts a posture where the handle 50 is inclined forward of the stroller 10 (inclined toward the front leg 22) from a position (position indicated by the chain lines in FIG. 3) in which the handle 50 is inverted on the rotational axis line (swing center) along the vertical axis when viewed from the lateral side, and the handle 50 is extended substantially in parallel with the rear legs 24. The operator can push and advance the stroller 10, grasping the handle 50 from a position on a side of the front legs 24 on which the operator faces the baby. At this time, the rear legs 24 of the stroller 10 face the forward side in the traveling direction.

On the other hand, by engaging the rear engagement projection 30 b and the engagement member 55 so as to be locked to each other, as shown in FIG. 2, the handle 50 is fixed on a second position (backside pushing position) P2. When the handle 50 is fixed on the second position P2, the handle 50 adopts a posture where the handle 50 is inclined rearward of the stroller 10 (inclined toward the rear legs 24) from a position (position indicated by the chain lines in FIG. 2) in which the handle 50 is inverted on the rotational axis line (swing center) along the vertical axis when viewed from the lateral side, and the handle 50 is extended substantially in parallel with the connecting rod 26. The operator can push and advance the stroller 10 with the baby facing forward in the traveling direction, grasping the handle 50 from a position on a side of the rear legs 24 of the stroller 10, i.e., from a back side of the baby. At this time, the front legs 22 of the stroller 10 face the forward side in the traveling direction.

The stroller 10 having the overall structure as described above can be folded by rotating the respective constituent members. To be specific, by pulling upward the handle 50 on the second position P2 at first, and then by pushing downward the handle 50, the bracket 34 is rotated clockwise in FIG. 2 with respect to the rear leg 24. In accordance with this operation, the armrest 28 and the lateral side connecting member 32 are rotated clockwise in FIG. 2 with respect to the connecting rod 26. By means of these operations, the handle 50 and the front leg 22 become substantially in parallel with each other when viewed from the lateral side, and the position of the handle 50 can be lowered. In this manner, the stroller 10 can be folded, so that the dimensions of the stroller can be reduced in the back and forth direction and in the up and down direction. On the other hand, in order to unfold the folded stroller 10, the above folding steps are reversely performed.

Next, the caster mechanism for front leg 60 is described with reference to FIGS. 4 to 7. As described above, the caster mechanisms for front leg 60 are disposed on the respective lower ends of the pair of front legs 22. The two caster mechanisms for front leg 60 have the same structure. As shown in FIGS. 4 to 6, the caster mechanism 60 includes: a front wheel (wheel) 61; a wheel holder 62 that holds the front wheel 61 so as to be rotatable in the back and forth direction of the stroller 10 and so as to be turnable relative to the back and forth direction of the stroller 10; and a locking means 75 disposed on the wheel holder 62, and capable of moving between a locking position P11 for restricting the turning of the wheel 61, and an unlocking position P12 for enabling the turning of the wheel 61. As shown in FIGS. 5 and 6, the wheel holder 62 includes: a base part 63 fixed on the front leg 22; a shaft member 66 fixed on the base part 63 through a pin 63 a; and a holding part 67 connected to the shaft member 66.

The holding part 67 has a first member 68 connected to the shaft member 66 through a bearing 70, and a second member 72 connected to the first member 68 through a pin 72 a. The shaft member 66 is extended substantially perpendicularly to the ground on which the stroller 10 in the unfolded state rests. The first member 68 is rotatable with respect to the shaft member 66 through the bearing 70 about a longitudinal axis line of the shaft member 66. The second member 72 holds a rotational shaft 73. Disposed respectively on opposed ends of the rotational shaft 73 are the front wheels 61. Namely, the second member 72 holds the wheels 61 disposed on opposed sides of the second member 72 such that the wheels 61 can be rotated. With the rotation of the first member 68 with respect to the shaft member 66, the wheels 61 can be turned relative to the back and forth direction of the stroller 10. In FIGS. 4 to 6, illustration of one of the front wheels 61 is omitted.

The rotational shaft 73 is laterally extended at a position displaced from the axis line of the shaft member 66 along the back and forth direction of the stroller 10. Thus, when the stroller 10 is steered, the front wheels 61 can be turned relative to the back and forth direction of the stroller 10 such that the axis line of the shaft member 66 is positioned forward of the rotational shaft 73 in the traveling direction. FIG. 5 shows the caster mechanism 60 when the stroller 10 is steered with the front leg 22 facing forward in the traveling direction, and FIG. 6 shows the caster mechanism 60 when the stroller 10 is steered with the rear leg 24 facing forward in the traveling direction.

As shown in FIGS. 4 to 6, between the first member 68 and the second member 72, there is disposed a resilient member 71 formed of, e.g., rubber. The resilient member 71 absorbs irregularities of a road on which the stroller 10 travels, to thereby improve stability and comfortableness of the stroller 10. A braking member 74 is swingably disposed on the second member 72 through a pin 74 a. When the braking member 74 is swung with respect to the second member 72, the braking member 74 is brought into contact with the wheel 61 so as to stop rotation of the wheel 61. Namely, the braking member 74 serves as a brake of the stroller 10.

As shown in FIGS. 5 and 6, the base part 63 is provided with the locking member 75 serving as the locking means. One end 75 a of the locking member 75 is connected to the base part 63 through a pin 76. The locking member 75 is swingable with respect to the base part 63 about the pin 76. As shown in FIGS. 5 and 6, the locking member 75 can be moved between the locking position P11 at which the locking member 75 is engaged with the holding part 67, and the unlocking position P12 at which the locking member 75 is not engaged with the holding part 67. As described in detail below, the locking member 75 is connected to a lock switching member 110 of a first switch mechanism 100 a through a first transmission means 120. The first transmission means 120 passes through an inside of the front leg 22 so as to be extended to the armrest 28 on which the first switch mechanism 100 a is supported (see, FIG. 10). As described below, switching of the locking member 75 between the locking position P11 and the unlocking position P12 is performed by operating the first switch mechanism 100 a through the first transmission means 120.

As clearly shown in FIGS. 6 and 7, a part of the first member 68 to be engaged with the locking member 75 is formed to have a substantially cylindrical shape. As shown in FIG. 7, a recess 69 b for receiving the locking member 75 is formed in a part of a cylindrical outer circumferential surface 69 a. The locking position P11 of the locking member 75 is a position where the locking member 75 is fitted in the recess 69 b so as to restrict the rotation of the first member 68 with respect to the shaft member 66.

In this structure, when the locking member 75 is arranged on the locking position P11, the turning movement of the wheel 61 relative to the back and forth direction of the stroller 10 is restricted. Hereafter, the state in which the turning movement of the wheel is restricted is also referred to simply as “locking condition”. As shown in FIG. 6, when the locking member 75 is fitted in the recess 69 b of the first member 68, the rotational shaft 73 is laterally extended so that the front wheel 61 is parallel to the back and forth direction of the stroller 10, and the axis line of the shaft member 66 is positioned nearer the rear leg 24 than the axis line of the rotational shaft 73. On the other hand, when the locking member 75 is arranged on the unlocking position P12, the first member 68 can be rotated with respect to the shaft member 66 so that the restriction of the turning movement of the front wheel 61 with respect to the back and forth direction is released.

The locking member 75 is urged by a torsion spring, not shown, from the unlocking position P12 toward the locking position P11. Thus, when the first transmission means 120 is in a relaxed condition, the locking member 75 is in contact with the cylindrical outer circumferential surface 69 a, or fitted in the recess 69 b.

Next, there are described, with reference to FIGS. 8 and 9, the caster mechanisms for rear leg 80 disposed on the respective lower ends of the pair of rear legs 24. The two caster mechanisms for rear leg 80 have the same structure. In addition, the caster mechanism for rear leg 80 has substantially the same structure as that of the caster mechanism for front leg 60. Namely, as shown in FIGS. 8 and 9, the caster mechanism 80 includes: a rear wheel (wheel) 81; a wheel holder 82 that holds the rear wheel 81 so as to be rotatable in the back and forth direction of the stroller 10 and so as to be turnable relative to the back and forth direction of the stroller 10; and a locking means 95 disposed on the wheel holder 82, and capable of moving between a locking position P21 for restricting the turning of the wheel 81, and an unlocking position P22 for enabling the turning of the wheel 81. As shown in FIG. 9, the wheel holder 82 includes: a base part 83 fixed on the rear leg 24; a shaft member 86 fixed on the base part 83 through a pin 83 a; and a holding part 87 connected to the shaft member 86.

As shown in FIG. 9, the holding part 87 has a first member 88 connected to the shaft member 86 through a bearing 90, and a second member 92 connected to the first member 88 through a pin 92 a. The shaft member 86 is extended substantially perpendicularly to the ground on which the stroller 10 in the unfolded state rests. The second member 92 rotatably holds the pair of wheels 81 through a rotational shaft 93. With the rotation of the first member 88 with respect to the shaft member 86, the wheels 81 can be turned relative to the back and forth direction of the stroller 10. In FIGS. 8 and 9, illustration of one of the rear wheels 81 is omitted.

The rotational shaft 93 is laterally extended at a position displaced from the axis line of the shaft member 86 along the back and forth direction of the stroller 10. Thus, the wheels 81 can be easily turned relative to the back and forth direction in accordance with changes of the traveling direction of the stroller 10. As shown in FIGS. 8 and 9, between the first member 88 and the second member 92, there is disposed a resilient member 91 formed of e.g., rubber. In addition, a braking member 94 is swingably disposed on the second member 92 through a pin 94 a.

As shown in FIG. 9, the base part 83 is provided with the locking member 95 serving as the locking means. One end 95 a of the locking member 95 is connected to the base part 83 through a pin 96. The locking member 95 is swingable with respect to the base part 83 about the pin 96. As shown in FIG. 9, the locking member 95 can be moved between the locking position P21 at which the locking member 95 is engaged with the holding part 87, and the unlocking position P22 at which the locking member 95 is not engaged with the holding part 87. As described in detail below, the locking member 95 is connected to the lock switching member 110 of the second switch mechanism 100 b through a second transmission means 130. The second transmission means 130 passes through an inside of the rear leg 24 so as to be extended to the armrest 28 on which the second switch mechanism 100 b is supported (see, FIG. 10). As described below, switching of the locking member 95 between the locking position P21 and the unlocking position P22 is performed by operating the second switch mechanism 100 b through the second transmission means 130.

Similarly to the caster mechanism for front leg 60, a part of the first member 88 to be engaged with the locking means 95 is formed to have a substantially cylindrical shape. A recess 89 b for receiving the locking member 95 is formed in a part of a cylindrical outer circumferential surface 89 a. The locking position P21 of the locking member 95 is a position where the locking member 95 is fitted in the recess 89 b so as to restrict the rotation of the first member 88 with respect to the shaft member 86. As shown in FIG. 9, when the locking member 95 is fitted in the recess 89 b of the first member 88, the rotational shaft 93 is laterally extended so that the rear wheel 81 is parallel to the back and forth direction of the stroller 10, and the axis line of the shaft member 86 is positioned nearer the front leg 22 than the axis line of the rotational shaft 93.

The locking member 95 is urged by a torsion spring, not shown, from the unlocking position P22 toward the locking position P21. Thus, when the second transmission means 130 is in a relaxed condition, the locking member 95 is in contact with the cylindrical outer circumferential surface 89 a, or fitted in the recess 89 b.

Next, the switch mechanisms 100 a and 100 b are described. As shown in FIGS. 2, 3, and 10, in this embodiment, each of the right and left armrests 28 of the frame part 20 is respectively equipped with the first switch mechanism 100 a and the second switch mechanism 100 b. In this embodiment, although located on different positions on the armrest 28, the first switch mechanisms 100 a and the second switch mechanisms 100 b have the same structure.

As shown in FIGS. 2, 3, and 10, each of the switch mechanisms 100 a and 100 b includes a casing 102, and the lock switching member 110 placed in the casing 102. The lock switching member 110 and the casing 102 are formed to have an elongated shape. The lock switching member 110 is configured to be slid in the casing 102 along a longitudinal direction thereof so as to project from the casing 102.

As shown in FIG. 10, a hollow portion 112 is formed in each of the lock switching members 110 so as to be extended along a longitudinal direction thereof. On the other hand, in the casing 102, there is placed a projection 104 fixed on the armrest The projection 104 is located in the hollow portion 112 of the lock switching member 110 that can be moved in the casing 102. Thus, a movable range of the lock switching member 110 is defined by the position of the projection 104 and the shape of the hollow portion 112. In addition, disposed in the hollow portion 112 is a compression spring 106 that is compressed between the projection 104 and the lock switching member 110. The lock switching member 110 is urged by the compression spring 106 so as to project outward from the casing 102.

As shown in FIG. 10, the lock switching member 110 of the first switch mechanism 100 a is located on the armrest 28 at a position near the engagement member 30 a on the front side. The handle 50 swung toward the first position P1 comes into contact with the lock switching member 110 of the first switching member 100 a and further pushes the lock switching member 110, so that the lock switching member 110 of the first switch mechanism 100 a is slid into the casing 102. In addition, the slidable direction of the lock switching member 110 of the first switch mechanism 100 a (i.e., the longitudinal direction of the lock switching member 110) is substantially parallel to a moving trajectory (L1 in FIG. 10) of a portion of the handle 50 to be in contact with the lock switching member 110 when the handle 50 is swung toward the first position P1 and is brought into contact with the lock switching member 110. In this embodiment, the first switch mechanism 100 a is positioned on the armrest 28 such that the longitudinal direction of the lock switching member 110 is substantially perpendicular to the longitudinal direction of the linear portion 51 a of the handle 50 which is arranged on the first position P1.

On the other hand, as shown in FIG. 10, the lock switching member 110 of the second switch mechanism 100 b is located on the armrest 28 at a position near the engagement member 30 b on the rear side. The handle 50 to be positioned on the second position P2 comes into contact with the lock switching member 110 of the second switch mechanism 100 b and further pushes the lock switching member 110, so that the lock switching member 110 of the second switching mechanism 100 b is slid into the casing 102. In addition, the slidable direction of the lock switching member 110 of the second switch mechanism 100 b (i.e., the longitudinal direction of the lock switching member 110) is substantially parallel to a moving trajectory (L2 in FIG. 10) of a portion of the handle 50 to be in contact with the lock switching member 110 when the handle 50 is swung toward the second position P2 and is brought into contact with the lock switching member 110. In this embodiment, the second switch mechanism 100 b is positioned on the armrest 28 such that the longitudinal direction of the lock switching member 110 is substantially perpendicular to the longitudinal direction of the linear portion 51 a of the handle 50 which is arranged on the second position P2.

Next, the transmission means 120 and 130 are described. As described above, the two first transmission means 120 are respectively disposed between the right side and the left caster mechanisms for front leg 60 and the first switch mechanisms 100 a. The two first transmission mechanisms 120 have the same structure. Meanwhile, the two second transmission means 130 are respectively disposed between the right side and the left caster mechanisms for rear leg 80 and the second switch mechanisms 100 b. The two second transmission means 130 have the same structure. The respective transmission means 120 and 130 are configured to transmit moving actions of the lock switching members 110 to the locking means 75 and 95, so as to move the locking means 75 and 95 from the unlocking positions P12 and P22 to the locking positions P11 and P21, or from the locking positions P11 and P21 to the unlocking positions P12 and P22. In this embodiment, the first transmission means 120 and the second transmission means 130 have the same structure, although the location thereof are different from each other.

The first transmission means 120 includes a lead wire 122 whose opposed ends are respectively fixed to the lock switching member 110 of the first switch mechanism 100 a and the locking means 75 of the caster mechanism for front leg 60, and a tubular member 124 through which the lead wire 122 passes. As shown in FIGS. 5, 6, and 10, opposed ends of the tubular member 124 are fixed on the armrest 28 (relative to the casing 102 of the first switch mechanism 100 a) and the base part 63 of the caster mechanism for front leg 60. The tubular member 124 is extended between the caster mechanism for front leg 60 and the armrest 28 through the front leg 22. The tubular member 124 is suitably held and fixed on the frame part 20 between the caster mechanism for front leg 60 and the armrest 28. The lead wire 122 is slidable in the tubular member 124. Namely, the lead wire 122 can be relatively moved, with respect to the tubular member 124, toward the side of the armrest 28 and toward the side of the caster mechanism for front leg 60.

Due to this structure, when the lock switching member 110 of the first switch mechanism 100 a is urged by the compression spring so as to project from the casing 102, the lead wire 122 is, in accordance with the movement of the lock switching member 110, drawn outside the tubular member 124 from the end of the tubular member 124 on the side of the armrest 28, and is drawn into the tubular member 124 from the end of the tubular member 124 on the side of the caster mechanism 60. As a result, the locking means 75 connected to the end of the lead wire 122 on the side of the caster mechanism 60 can be moved from the locking position P11 to the unlocking position P12.

Reversely, when the lock switching member 110 of the first switch mechanism 100 a is pushed into the casing 102 by the handle 50, the lead wire 122 is, in accordance with the movement of the lock switching member 110, pushed into the tubular member 124 from the end of the tubular member 124 on the side of the armrest 28, and is pushed outside the tubular member 124 from the end of the tubular member 124 on the side of the caster mechanism 60. As a result, the locking member 75 connected to the end of the lead wire 122 on the side of the caster mechanism 60 can be moved from the unlocking position P12 to the locking position P11.

On the other hand, the second transmission means 130 includes a lead wire 132 whose opposed ends are respectively fixed to the lock switching member 110 of the second switch mechanism 100 b and the locking means 95 of the caster mechanism for rear leg 80, and a tubular member 134 through which the lead wire 132 passes. As shown in FIGS. 9 and 10, opposed ends of the tubular member 134 are fixed on the armrest 28 (relative to the casing 102 of the second switch mechanism 100 b) and the base part 83 of the caster mechanism for rear leg 80. The tubular member 134 is extended between the caster mechanism for rear leg 80 and the armrest 28 through the rear leg 24. The tubular member 134 is suitably held and fixed on the frame part 20 between the caster mechanism for rear leg 80 and the armrest 28. The lead wire 132 is slidable in the tubular member 134. Namely, the lead wire 132 can be relatively moved, with respect to the tubular member 134, toward the side of the armrest 28 and toward the side of the caster mechanism for rear leg 80.

Due to this structure, when the lock switching member 110 of the second switch mechanism 100 b is urged by the compression spring so as to project from the casing 102, the lead wire 132 is, in accordance with the movement of the lock switching member 110, drawn outside the tubular member 134 from the end of the tubular member 134 on the side of the armrest 28, and is drawn into the tubular member 134 from the end of the tubular member 134 on the side of the caster mechanism 80. As a result, the locking means 95 connected to the end of the lead wire 132 on the side of the caster mechanism 80 can be moved from the locking position P21 to the unlocking position P22.

Reversely, when the lock switching member 110 of the second switch mechanism 100 b is pushed into the casing 102 by the handle 50, the lead wire 132 is, in accordance with the movement of the lock switching member 110, pushed into the tubular member 134 from the end of the tubular member 134 on the side of the armrest 28, and is pushed outside the tubular member 134 from the end of the tubular member 134 on the side of the caster mechanism 80. As a result, the locking means 95 connected to the end of the lead wire 132 on the side of the caster mechanism 80 can be moved from the unlocking position P22 to the locking position P21.

The forces of the compression springs 106 urging the lock switching members 110 of the respective switch mechanisms 100 a and 100 b are greater than forces of torsion springs (not shown), which are disposed on the caster mechanisms, for swinging the respective locking members 75 and 95 so as to draw out the lead wires 122 and 132 toward the side of the caster mechanisms 60 and 80. Thus, when no external force is applied to the lock switching members 110 of the switch mechanisms 100 a and 100 b, the respective lead wires 122 and 132 are in a strained condition, and the lock switching members 110 project from the casings 102, so that the locking members 75 and 95 are arranged on the unlocking positions P12 and P22, respectively.

Next, there is described an operation of the stroller 10 as structured above, when the handle 50 is swung.

As described above, by engaging the engagement members 55 of the handle 50 with the front engagement members 30 a disposed on the armrests 28, the handle 50 can be fixed on the first position P1 (see, FIG. 3) in which the handle 50 is inclined toward the front legs 22. In this state, a parent can steer the stroller 10 with the rear legs 24 facing the forward side in the traveling direction, grasping the handle 50 on the first position P1 from the side of the front legs 22 of the stroller 10. Alternatively, by engaging the engagement members 55 of the handle 50 with the rear engagement projections 30 b disposed on the armrests 28, the handle 50 can be fixed on the second position (see, FIG. 2). In this state, the parent can steer the stroller 10 with the front legs 22 facing the forward side in the traveling direction, grasping the handle 50 on the second position P2 from the side of the rear legs 24 of the stroller 10. In both cases where the stroller 10 is moved with the front legs 22 or the rear legs 24 facing forward in the traveling direction, it is preferable that, from the view point of manipulability and traveling stability, the wheels facing the forward side in the traveling direction are turnable relative to the back and forth direction, and that the wheels facing the rearward side in the traveling direction are restricted from turning relative to the back and forth direction. In the above stroller, the wheels of the caster mechanisms for front leg 60 and the caster mechanisms for rear leg 80 can be automatically switched, in accordance with a position of the handle 50, between the turnable condition and the unturnable condition, in a stable and reliable manner.

Firstly, a case in which the handle 50 is swung from the second position P2 toward the first position P1 is described in detail. When the swinging of the handle 50 is started, the lock switching member 110 of the second switch mechanism 100 b, which has been received in the casing 102, is urged by the compression spring 106 so as to project from the casing 102, in accordance with the swinging of the handle 50. Upon projection of the lock switching member 110 of the second switch mechanism 100 b from the casing 102, the locking member 95 of the caster mechanism for rear leg 80 is moved from the locking position P21 to the unlocking position P22, as described above. As a result, the rear wheel 81 automatically comes into the turnable condition.

When the handle 50 is further swung toward the first position P1, the handle 50 is brought into contact with the lock switching member 110 of the first switch mechanism 100 a. When the handle 50 is further swung so that the sliding member 55 of the handle 50 is engaged with the engagement member 30 a disposed on the armrest 28, the handle 50 presses the lock switching member 110 of the first switch mechanism 100 a and pushes the lock switching member 110 into the casing 102. At this time, the slidable direction of the lock switching member 110 is substantially parallel to the moving trajectory (L1 in FIG. 10) of a portion of the handle 50 to be in contact with the lock switching member 110 when the handle 50 is brought into contact with the lock switching member 110. That is to say, since the direction in which the handle 50 pushes the lock switching member 110 and the slidable direction of the lock switching member 110 substantially correspond to each other, the lock switching member 110 can be significantly smoothly moved by swinging the handle 50. Moreover, according to this embodiment, the lock switching member 110 of the first switch mechanism 100 a is positioned near the engagement member 30 a on the front side. Thus, the lock switching member 110 will not be affected by any influence such as flexure of the respective constituent members, but can be pushed in a stable and reliable manner by the handle 50 that is swung toward the first position P1.

As described above, after the lock switching member 110 of the first switch mechanism 100 a is pushed into the casing 102 by the handle 50, the lead wire 122 is relaxed on the side of the caster mechanism for front leg 60 of the tubular member 124, so that the locking member 75 is brought into contact with the cylindrical outer circumferential surface 69 a of the first member 68. Then, by steering the stroller 10 with the rear legs 24 of the stroller 10 facing the forward side in the traveling direction, the wheels 61 are turned relative to the back and forth direction of the stroller 10, such that the rotational shaft 73 of the front wheels 61 is laterally extended so that the front wheels 61 are parallel to the back and forth direction of the stroller 10, and the axis line of the shaft member 66 of the caster mechanism for front leg is positioned nearer the rear leg 24 than the rotational shaft 83. Thus, the locking member 75 is slid along the cylindrical outer circumferential surface 69 a of the first member 68 so as to be fitted in the recess 69 b, whereby the locking member 75 of the caster mechanism for front leg 60 is arranged on the locking position P11. As a result, the front wheel 61 automatically comes into the unturnable condition.

In this manner, when the handle 50 is swung from the second position P2 toward the first position P1, the front wheels can be switched from the turnable condition to the unturnable condition in a stable and reliable manner. At the same time, the rear wheels 81 can be switched from the unturnable condition to the turnable condition in a stable and reliable manner.

Secondly, a case in which the handle 50 is swung from the first position P1 toward the second position P2 is described in detail. When the swinging of the handle 50 is started, the lock switching member 110 of the first switch mechanism 100 a is urged by the compression spring 106 so as to project from the casing 102. Upon projection of the lock switching member 110 of the first switch mechanism 100 a from the casing 102, the locking member 75 of the caster mechanism for front leg 60 is moved from the locking position P11 to the unlocking position P12, as described above. As a result, the front wheel 61 automatically comes into the turnable condition.

When the handle 50 is further swung so that the sliding member of the handle 50 is engaged with the engagement member 30 b disposed on the armrest 28, the handle 50 presses the lock switching member 110 of the second switch mechanism 100 b and pushes the lock switching member 110 into the casing 102. At this time, the slidable direction of the lock switching member 110 is substantially parallel to the moving trajectory (L2 in FIG. 10) of a portion of the handle 50 to be in contact with the lock switching member 110 when the handle 50 is brought into contact with the lock switching member 110. Moreover, the lock switching member 110 of the second switch mechanism 100 b is positioned near the engagement member 30 b on the rear side. Thus, the lock switching member 110 can be smoothly pushed in a stable and reliable manner by the handle 50 that is swung toward the second position P2.

As described above, after the lock switching member 110 of the second switch mechanism 100 b is pushed into the casing 102 by the handle 50, the lead wire 132 is relaxed on the side of the caster mechanism for rear leg 80 of the tubular member 134, so that the locking member 95 is brought into contact with the cylindrical outer circumferential surface 89 a of the first member 88. Then, by steering the stroller 10 with the front legs 22 facing the forward side in the traveling direction, the locking member 95 is slid along the cylindrical outer circumferential surface 89 a of the first member 88 so as to be fitted in the recess 89 b, whereby the locking member 95 of the caster mechanism for rear leg 80 is arranged on the locking position P21. As a result, the rear wheel 81 automatically comes into the unturnable condition.

In this manner, when the handle 50 is swung from the first position P1 toward the second position P2, the front wheels can be switched from the unturnable condition to the turnable condition in a stable and reliable manner. At the same time, the rear wheels 81 can be switched from the turnable condition to the unturnable condition in a stable and reliable manner.

According to this embodiment, the switch mechanisms 100 a and 100 b can be supported on suitable positions by the armrest 28 in accordance with the swingable range of the handle 50. Thus, by swinging the handle 50, the lock switching members 110 of the switch mechanisms 100 a and 100 b can be smoothly moved. Accordingly, the conditions of the wheels 61 and 81 can be switched in accordance with the position of the handle 50 in a more stable and reliable manner.

Further, according to this embodiment, there are separately disposed: the switch mechanism 100 a for operating the locking means 75 of the caster mechanism for front leg 60, and the transmission means 120 therefor; and the switch mechanism 100 b for operating the locking means 95 of the caster mechanism for rear leg 80, and the transmission means 130 therefor. Thus, the moving actions of the lock switching members 110 can be transmitted to the respective locking means 75 and 95 through the transmission means 120 and 130 in a more stable and reliable manner. Accordingly, the lock switching members 110 and the locking means 75 and 95 can be more smoothly moved by the swinging of the handle 50.

Furthermore, according to this embodiment, since the tubular members 124 and 134 are extended in the front leg 22 or the rear leg 26 of the frame part 20. According to such a stroller 10, a larger part of the transmission means 120 and 130 can be prevented from being exposed outside. Thus, when the stroller 10 is folded, for example, the transmission means 120 and 130 can be prevented from being caught by other constituent members or outside parts.

The above-described embodiment can be variously modified within a scope of the present invention. An example of such a modification is described below.

In the above embodiment, the locking means 75 and 95 are disposed on both of the caster mechanism for front leg 60 and the caster mechanism for rear leg 80, which is given as an example. Not limited thereto, the locking means may be disposed only on one of the caster mechanism for front leg 60 and the caster mechanism for rear leg 80. In this case, the wheel of the caster mechanism free of locking means may be configured to be turnable relative to the back and forth direction of the stroller 10, or may be configured to be parallel to the back and forth direction of the stroller 10 so as to be unturnable.

In addition, the overall structure of the stroller 10 described in the above embodiment is merely an example. For example, the frame part 20 may be structured so as not to be foldable.

Further, the structure of the caster mechanism described in the above embodiment is merely an example. For example, it is possible to employ the structure of the caster mechanism disclosed in JP2002-284015A.

Furthermore, in the above embodiment, the tubular members 124 and 134 are extended in the front leg 22 or the rear leg 24 of the frame part 20, which is given as an example. Not limited thereto, the tubular members 124 and 134 may be held on an outer surface of the front leg 22 or an outer surface of the rear leg 24. According to such a stroller, routing lines of the transmission means 120 and 130 can be more freely determined. In addition, since the routing lines of the transmission means 120 and 130 can be simplified, the wires 122 and 132 can be smoothly slid in the tubular members 124 and 134.

Moreover, in the embodiment as described above, although the first switch mechanism 100 a is connected to the caster mechanism for front leg 60 and the second switch mechanism 100 b is connected to the caster mechanism for rear leg 80, the arrangement is not limited thereto. The second switch mechanism 100 b may be connected to the caster mechanism for front leg 60, and the first switch mechanism 100 a may be connected to the caster mechanism for rear leg 80. Although it has been described by way of example that the lock switching mechanisms 110 of the respective switch mechanisms 100 a and 100 b are urged by the compression springs 106 such that the lead wires 122 and 132 are drawn to the side of the armrest 28, the arrangement is not limited thereto. The lock switching members 100 of the respective switch mechanisms 100 a and 100 b may be urged by the compression springs 106 such that the lead wires 122 and 132 are pushed into the tubular members 124 and 134 toward the sides of the caster mechanisms 60 and 80. 

1. A stroller comprising: a frame part including an armrest, a front leg, and a rear leg, the front leg and the rear leg being connected to the armrest; a handle connected to the frame part so as to be swingable between a first position and a second position; a caster mechanism disposed at least on one of the front leg and the rear leg, the caster mechanism including a wheel, a wheel holder configured to rotatably and turnably hold the wheel, and a locking means capable of moving between a locking position for restricting a turning of the wheel and an unlocking position for enabling the turning of the wheel; a switch mechanism supported on the armrest of the frame part and, the switch mechanism including a lock switching member capable of being pushed so as to be moved by the handle that is swung toward the first position or the second position; and a transmission means disposed between the switch mechanism and the caster mechanism and configured to transmit a moving action of the lock switching member to the locking means so as to move the locking means from the unlocking position to the locking position or from the locking position to the unlocking position.
 2. The stroller according to claim 1, wherein a movable direction of the lock switching member is substantially parallel to a moving trajectory of a portion of the handle to be contact with the lock switching member when the handle is brought into contact with the lock switching member.
 3. The stroller according to claim 1, wherein: the caster mechanism includes a caster mechanism for front leg disposed on a lower end of the front leg, and a caster mechanism for rear leg disposed on a lower end of the rear leg; the switch mechanism includes a first switch mechanism to be engaged with the handle resting on the first position and a second switch mechanism to be engaged with the handle resting on the second position, the first switch mechanism and the second switch mechanism being supported on the armrest; and the transmission means includes a first transmission means disposed between the first switch mechanism and one of the caster mechanism for front leg and the caster mechanism for rear leg, and a second transmission means disposed between the second switch mechanism and the other of the caster mechanism for front leg and the caster mechanism for rear leg.
 4. The stroller according to claim 3, wherein when the handle rests on the second position, the turning of the wheel of the caster mechanism for rear leg is restricted, and when the handle rests on the first position, the turning of the wheel of the caster mechanism for front leg is restricted.
 5. The stroller according to claim 4, wherein the handle is configured to be inclined forward on the first position and inclined rearward on the second position.
 6. The stroller according to claim 3, wherein an engagement member is disposed on the armrest, the engagement member capable of being engaged with the handle so as to lock the handle on the first position, and the lock switching member of the first switch mechanism is positioned near the engagement member.
 7. The stroller according to claim 3, wherein an engagement member is disposed on the armrest, the engagement member capable of being engaged with the handle so as to lock the handle on the second position, and the lock switching member of the second switch mechanism is positioned near the engagement member.
 8. The stroller according to claim 1, wherein: the transmission means includes a wire whose opposed ends are respectively fixed to the lock switching member of the switch mechanism and the locking means of the caster mechanism, and a tubular member held by the frame part; and the wire passes through the tubular member so as to be slidable with respect to the tubular member.
 9. The stroller according to claim 8, wherein the tubular member is extended in the front leg or the rear leg of the frame part.
 10. The stroller according to claim 8, wherein the tubular member is held on an outer surface of the front leg or an outer surface of the rear leg of the frame part. 